UDP通信

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.SocketException;
public class DatagramDemo {
	public static void main(String[] args) {
		try {
			//1、创建客户端口
			DatagramSocket server=new DatagramSocket(6666);
			//2、准备数据
			String msg="传输数据";
			byte[] data=msg.getBytes();
			//3、打包数据、发送位置
			DatagramPacket packet =new DatagramPacket(data, data.length,new InetSocketAddress("localhost", 8989));
			//4、发送
			server.send(packet);
			server.close();
		} catch (SocketException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}	
	}
}

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class DatagramScoketDemo {
	public static void main(String[] args) {
		try {
			//1、创建服务端端口
			DatagramSocket server=new DatagramSocket(8989);
			//2、准备接受容器
			byte[] datas=new byte[1024];
			//3、封装成包
			DatagramPacket packet=new DatagramPacket(datas, datas.length);
			//4、接受数据
			server.receive(packet);
			//5、分析数据
			byte[] data=packet.getData();
			int len=packet.getLength();
			System.out.println(new String(data,0,len));
			//关闭
			server.close();
		} catch (SocketException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}